Folding box

ABSTRACT

A folding box is set up from a blank coated on one side with a thermoplastic material, having a rear wall with an articulated lid and closure flap, two side walls, and a front wall, the side and upper edges of the side walls and the upper edge of the front wall being bent outwardly to form closure borders.

United States Patent 1191 Graser [4 Aug. 13, 1974 FOLDING BOX [56]References Cited [75] Inventor: Adelbe rt Graser, Spiegel, Koniz, UNITEDSTATES PATENTS Switzerland 2,142,166 1/1939 Zalkind 229/48 R 2,192,7223/1940 Vogt 229/48 T [73] Assgnee- Stage" Llthographlea 2,409,46010/1946 Waters 229/48 T Drinker, Canton of Beme 2,920,807 1/1960 Bruce229/33 Switzerland 3,511,433 5/1970 Andrews et al. 229/44 R 22 Pl d: .41 7 1 16 Jan 4 9 3 Primary ExaminerWilliam I. Price [21] Appl. No.:320,993 Assistant ExaminerDouglas B. Farrow Attorney, Agent, orFirmMarshall & Yeasting [30] Foreign Application Priority Data SACT Jan.20, 1972 Swltzerland 857/72 A foldin box s Set u from a blank coated onone g [52] us. C]. 229/33 229/30 229/32 slde w1th a thermoplastlcmaterial, havlng a rear wall R 226/48 R 29/48 with an articulated lidand closure flap, two side walls, [51] Int Cl B65d 5/22 and a frontwall, the side and upper edges of the side [58] w T 48 R walls and theupper edge of the front wall being bent outwardly to form closureborders.

1 Claim, 1 Drawing Figure and the underside of the cover, respectively.

FOLDING BOX BACKGROUND OF THE INVENTION Folding boxes intended to besuitable for storing deep-frozen products must possess a whole series ofproperties. These include, above all, absolute fluidtightness and henceextremely good adhesion at the points of welding. This, in turn, can beachieved only if coated surfaces face each other at all points ofwelding, and if a sufficient amount of pressure can be applied, which isnot always possible when the welding tongs cannot grasp from both sidesthe two folded portions to be welded. A further prerequisite for theutility of a folding box serving to store deep-frozen products is theabsence of multiple layers at the pointsof welding, for these alwayslead to leakage. Furthermore, no raw-cut edges may extend into theinterior of the box since otherwise, if the packaged product partiallythaws, the liquid can penetrate into the material at the cuts anddiscolor it.

Finally, to permit the manufacture of such a folding box at a reasonableprice, i. e., to be able to use relatively thin cardboard, the foldingbox must have a certain stiffness and lend itself to being machine-madein a simple manner.

Previously known boxes of this type never met the aforementionedprerequisites more than partially.

su MARY ogrnE INVENTION It is the object of the present invention tocreate a box of this type which is advantageous from all of the saidpoints of view. The invented folding box is characterized in that theside edges of the side walls and the upper edges of the side and frontwalls have outwardly bent closure borders which, when the box is closed,are joined to the inner sides of the rear wall and front wallDESCRIPTION OF THE DRAWINQ DESCRIPTION OF THE PREFERRED EMBODIMENT Thebox according to the invention is set up from a blank coated on one sidewith a conventional heatsealable material, the coated surfaces being onthe inside when the box is set up. The box has a bottom 1, from whichthe rear wall 2, the two side walls 3 and 4, and the front wall 5 arefolded upward, the lid 6 with the closure flap 7 being articulated torear wall 2. Another closure flap 8 is provided on front wall 5.

The upper edge and the two side edges of side walls 3 and 4 are bentoutward at a 90 angle to form closure borders 9-14, so that the coatedsurfaces of lateral closure borders 11-14 lie against the inner sides offront wall 5 and rear wall 2, respectively, and make possible afaultless weld.

The same favorable welding conditions exist for the closure of the box,when upper closure borders 9 and 10 of side walls 3 and 4 can be weldedto the underside of lid 6, and the two closure flaps 7 and 8 can bewelded together, in each of which cases the coated surfaces are facingone another.

In this way, the closed box is absolutely fluid-tight since the coatedsurfaces are against each other at all points of welding, multiplelayers do not occur anywhere, and, because the closure borders to bewelded project outward, they can be grasped from both sides by thewelding tongs and welded under comparatively high pressure.

Furthermore, this box has no raw-cut edges extending into its interior;and the bent-out closure borders of the side portions form an additionalstiffening which not only increases the stacking possibilities but alsoallows the use of a comparatively light cardboard.

I claim:

1. A folding box set up from a blank coated on one side with aheat-scalable material, having a rear wall with an articulated lid andclosure flap, two side walls and a front wall, the side edges of theside walls and the upper edges of the side walls and front wall beingbent outwardly to form closure borders which, when the box is closed,are joined to the inner sides of the front and rear walls and to theunderside of the cover, respectively.

1. A folding box set up from a blank coated on one side with aheat-sealable material, having a rear wall with an articulated lid andclosure flap, two side walls and a front wall, the side edges of theside walls and the upper edges of the side walls and front wall beingbent outwardly to form closure borders which, when the box is closed,are joined to the inner sides of the front and rear walls and to theunderside of the cover, respectively.